maybe this rather a silly question but I have not found anything helpful. I have two groups of samples which are basically a treatment and control group.

My task at hand is to compare a certain variable between those two groups, which however is not appearing after the treatment (t) but is rather at t-1.

Is PSM a valid method to find comparable matches for this comparison given that (a) it is expected that the variable of interest does not influence the probability of being in the treatment group and (b) that is expected to have an influence?

Many thanks in advance!

Felix